SPAD-Based Flash Lidar with High Background Light Suppression

In this contribution, we present the concept of a 4 x 128 pixel line sensor for direct time-of-flight measurement based on single-photon avalanche diodes (SPAD) fabricated in a high-voltage automotive 0.35 mu m CMOS process. An in-pixel time-to-digital converter with a resolution of 312.5 ps determines the arrival of photons reflected from targets in the area of view. Since we are employing a so-called first photon approach, there are no dead-time effects. In addition, our approach uses a variable photon coincidence detection to suppress effects of ambient illumination. As a test vehicle we have implemented a 1 x 80 pixel CMOS SPAD line sensor and characterized it.